|Observation data (J2000 epoch)|
|Right ascension||02h 39m 54.7s|
|Declination||−01° 33′ 32″|
|Distance||12.8 billion light years|
|Apparent magnitude (V)||24.24|
|Size||~10,000 ly (diameter)|
HCM-6A is a galaxy that was found in 2002 by a team led by Esther Hu from the University of Hawaii, using the Keck II Telescope in Hawaii. HCM-6A is located behind the Abell 370 galactic cluster, near M77  in the constellation Cetus, which enabled the astronomers to use Abell 370 as a gravitational lens to get a clearer image of the object.
HCM-6A was the farthest object known at the time of its discovery. It exceeded SSA22−HCM1 (z = 5.74) as the most distant normal galaxy known, and quasar SDSSp J103027.10+052455.0 (z = 6.28) as the most distant object known. In 2003, SDF J132418.3+271455 (z = 6.578) was discovered, and took over the title of most remote object known, most remote galaxy known, and most remote normal galaxy known.
- Halton Arp & David Russell (2001). "A Possible Relationship between Quasars and Clusters of Galaxies". The Astrophysical Journal. 549 (2): 802–819. Bibcode:2001ApJ...549..802A. doi:10.1086/319438.
- E. M. Hu, et al. (2001). "A Redshift z = 6.56 Galaxy behind the Cluster Abell 370". The Astrophysical Journal Letters. 568 (2): L75–L79. Bibcode:2002ApJ...568L..75H. arXiv: . doi:10.1086/340424.
- Press release, National Astronomical Observatory of Japan, September 13, 2006
|Most distant astronomical object
2002 — 2003
|Most distant galaxy
2002 — 2003